thank you guys for the valuable answers you gave me
to solve this problem I finally went into the program file folder /openerp7/ Service/ there are two files that are: server start and stop server . just double clic on stop and to start

Goto Start --> Run --> type services.msc and enter. A new window open that has a list of currently services in system. Select OpenERP Server. Right Click on that Services -- Shows the option such as Start, Stop, Restart.